| Budget Amount *help |
¥1,900,000 (Direct Cost: ¥1,900,000)
Fiscal Year 1988: ¥200,000 (Direct Cost: ¥200,000)
Fiscal Year 1987: ¥300,000 (Direct Cost: ¥300,000)
Fiscal Year 1986: ¥1,400,000 (Direct Cost: ¥1,400,000)
|
|---|
| Research Abstract |
The powdery metallic oxides are used in the industries as magnetic material, sensor, catalyst, abrasive, pigment and raw material for the ceramic production. The fact that the reactivity and the properties of the oxides are strongly dependent on the preparation conditions of them has been known, but the reasons are still not clear because of the complex interaction of many factors controlling the reactivity and the properties of the oxides. In this project, the relation between the preparation conditions and the reactivity for -Fe_2O_3, V_2O_5 and MnO_2 was investigated. With -Fe_2O_3, its reactivity was studied for the catalytic thermal decomposition of KC10_4 powder, the ferrite formation reactions with ZnO and MgO, and the effect of foreign metallic inos on -Fe_2O_3 formation from Fe(III)-hydroxides. with V_2O_5, its reactivity was studied for the powdery reaction with -Fe_2O_3 and SO_2. With MnO_2, the dissociation behavior of the surface hydroxyl group in the aqueous solutions was
… More
studied. The formation of hydroxide film on Al-metal and Zr(IV)-Cr(III) and Ti(IV)-Cr(III) composite oxide films on stainless steel were also investigated.
The increase in preparation temperature of -Fe_2O_3 powders resulted in the decrease in the catalytic activity and the formation rate of ZnFe_2O_4 and MgFe_2O_4 ferrites. It was found that for these reactions, the contact between the reactant particles affects the reactivity and ZnO which has relatively high volatility shows the high initial reactivity. The crystallization of amorphous Fe(III)-hydroxide to -Fe_2O_3 in the course of heating process was observed to be hindered by an addition of foreign metallic ions, such as Cu^<2+>, Ni^<2+>, Al^<3+>. The addition procedure (co-precipitation, gel-mixing and mortar-mixing) affected the degree of the hindering effect. With MnO_2, the dissociation constant of hydroxyl groups formed on the surface in aqueous solutions were determined by the acid-base titration of the suspensions containing MnO_2. It was found that FTIR-RAS method was helpful to analyse the structure of Al-hydroxide film formed on Al-metal by the anodizing. Less
|
